RV Repair: water heater, burner tube, 12 volt

Question
I have an Atwood 6 gallon electronic ignition water heater it lights intermittently it may light 3 or 4 times in a row then it will try to light but will not and the yellow light inside the coach stays on brightly if you turn it off and back on a few seconds later it may light or you may have to do it a couple of times but it does light A spark is present every time you can both hear and see it sparking it appears sometimes the gas is not flowing I have checked the orifice it appears clean I have cleaned the burner tube and all the contacts none of that has seemed to help I am guessing it is either the solenoid or the circuit board any suggestions on how to tell which or could it be something else

Answer
I have not worked on the Atwood but
I would check the voltage at this point and make sure you have at least 10.5 VDC minimum from the 12 volt line to run the water heater,
I have requested some tech sheets for this heater, when I get them I will forward them too you.

I found the guide for troubleshooting your type of water heater, , It is pretty thourough.
http://www.atwoodmobile.com/Service/Trouble/electric.cfm

They also have a video
http://www.atwoodmobile.com/Service/Trouble/waterheatervid.cfm

They also have the schematics for download, if you need help reading them I will download it and guide you through it
Let me know if this helps.